(1) A person who has sexual intercourse with another person commits the crime of rape in the first degree if:
(a) The victim is subjected to forcible compulsion by the person;
(b) The victim is under 12 years of age;
(c) The victim is under 16 years of age and is the person’s sibling, of the whole or half blood, the person’s child or the person’s spouse’s child; or
(d) The victim is incapable of consent by reason of mental incapacitation, physical helplessness or incapability of appraising the nature of the victim’s conduct.
(2) Rape in the first degree is a Class A felony.